Patrón de citocinas en hígado y bazo de perros con Leishmaniasis visceral natural

in the present study, we characterized the cytokine pattern in the spleen and liver of naturally infected dogs with leishmania infantum (chagasi) from the nueva esparta state of venezuela. the dogs were classified as symptomatic and asymptomatic considering three main signs of this disease: hepatosplenomegalia, cachexia and onichogriphosis. tissue samples from liver and spleen were taken to evaluate parasite load, cytokines and chemokines expression by immunohistochemistry. in symptomatic dogs, a higher parasitic load was observed in the liver and spleen as compared to asymptomatic dogs. in the spleen, the density of gamma interferón (ifn-g), interleukins (il-12, il-10, il-4, il-8) and monocyte chemoattractant protein-1 (mcp-1), it was similar between asymptomatic and symptomatic dogs. whereas, in the liver ifn-g, il-12, il-10 il-8 and mcp-1 showed a tendency to increase in symptomatic dogs, with a significant increment of il-4 + cells. in the liver, the density of il-4+ cells was positively correlated with hepatomegaly. in addition, higher concentrations of macrophage inflammatory protein 1 alpha (mip-1a) were observed in the serum of asymptomatic than in symptomatic dogs. these results corroborate the existence of an organ-specific immune respose against l. infantum (chagasi), with a t helper 2 (th2) immune response in the liver of symptomatic dogs, with prevalence of il-4 over ifn-g and il-12. the high production of il-4 is directly related with hepatomegalia.